EQUINE | Equine Disease Quarterly
The current gold standard for diagnosing besnoitiosis
in donkeys is histologic identification of Besnoitia
cysts within the skin of individuals displaying clinical
lesions, generally achieved via skin biopsy. B. bennetti
can be detected in blood via western blot and indirect
fluorescent antibody testing (IFAT), and antibody titers in
donkeys have been shown to be effective for identifying
infected donkeys. While these assays are not yet available
in the United States, they represent an effective and non-
invasive method for screening individual donkeys and
herd populations and would undoubtedly further our
understanding of the epidemiology and transmission of
besnoitiosis in the United States.
There are no known effective treatments for equine
besnoitiosis. Treatment with anti-protozoal medications
ponazuril,
trimethoprim-sulfamethozazole,
and
nitazoxanide have not been effective. The potential for
natural recovery from besnoitiosis and the long-term
prognosis for infected animals remains unknown. The
author has followed several infected donkeys for the past
5 years, none of which have spontaneously resolved.
Although besnoitiosis has not yet been reported in
horses in North America, cases have been described
in Africa, and the potential for similar infections in the
United States cannot be excluded as a possibility.
CONTACT:
Sally DeNotta, DVM, PhD, DACVIM
[email protected]
(352) 392-2229
College of Veterinary Medicine
University of Florida
Gainesville, Florida
Peripartum Death in Mares
Complications associated with foaling are a significant
cause of morbidity and mortality in both foals and
mares. Even apparently normal births can result in
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significant internal and external injury to the mare. In
extreme cases, these injuries can be severe and result in
death or require humane euthanasia of the dam.
A review of diagnostic case submissions to the University
of Kentucky Veterinary Diagnostic Laboratory was
conducted to assess equine peripartum deaths during
the 2017 and 2018 foaling seasons. Mares that died
secondary to foaling complications or were humanely
euthanized due to significant parturition associated
injury were included.
During the two-year period, 121 cases of peripartum
death were identified out of approximately 3,000
equine necropsy submissions. Cases were categorized
into five groups (gastrointestinal, musculoskeletal,
reproductive, vascular, and miscellaneous) based on
the primary organ system associated with the cause of
death. Submissions began in December and extended
into June of both years. Deaths occurred in multiple
breeds, but Thoroughbreds predominated.
Fatal lesions associated with the gastrointestinal tract
were most common and occurred in 52 (43%) cases.
Diseases with the highest incidence included cecal
rupture (12%), colonic torsion (7%), colonic rupture
(4%), rectal prolapse (3%), cecal impaction (3%), gastric
rupture (3%), rectal tear (3%), and non-infectious
inflammatory processes (3%). One to two cases of small
intestinal perforation, mesenteric rents and tears, and
colonic displacement were also identified.
Fatal vascular lesions accounted for 24% of peripartum
deaths and included the No. 1 cause of death during
the review period, rupture of the uterine artery.
Ruptures of the uterine artery were by far the most
common vascular lesion (17%), frequently resulted in
secondary hematoma formation in the broad ligament,
a connective tissue structure that supports the uterus,
and hemoperitoneum. Infrequent ruptures were also
• Equine Health Update •